The two weren’t rushing to announce to the world, but are becoming more comfortable with telling others.

“Yes, Khloe and Tristan are expecting and they are absolutely thrilled,” a source tells PEOPLE. “This isn’t something they were in a rush to announce to the whole world, and it’s only been in just the past week or so that they’ve felt comfortable telling most of their inner circle.

Currently, three of the sisters (Kim, Kylie and Khloe) are expecting children next year. Kylie is supposedly having a girl with Travis Scott and is due in February. Kim and Kanye are expecting their third child, which is a girl.